JAWRA Journal of the American Water Resources Association

How to Cite

Jacob, J. S. and Lopez, R. (2009), Is Denser Greener? An Evaluation of Higher Density Development as an Urban Stormwater-Quality Best Management Practice. JAWRA Journal of the American Water Resources Association, 45: 687–701. doi: 10.1111/j.1752-1688.2009.00316.x

Author Information

Respectively, Director of the Texas Coastal Watershed Program (Jacob), Department of Recreation, Parks, and Tourism Science, Texas A&M University, College Station, Texas [Jacob also holds a joint appointment with the Texas A&M Sea Grant Program and with the Texas AgriLife Extension Service]; and Faculty – Geospatial Modeler and Instructor (Lopez), Department of Medicine, Environmental Health Section – EHS, Chronic Disease Prevention and Control Research Center, Baylor College of Medicine, Houston, Texas.

Keywords:

urban areas;

watersheds;

urbanization;

water policy;

modeling;

best management practices;

stormwater management;

watershed management

Abstract: A simple spreadsheet model was used to evaluate potential water quality benefits of high-density development. The question was whether the reduced land consumed by higher density development (vs. standard suburban developments) would offset the worse water quality generated by a greater amount of impervious surface in the smaller area. Total runoff volume and per acre loadings of total phosphorous, total nitrogen, and total suspended solids increased with density as expected, but per capita loadings and runoff decreased markedly with density. For a constant or given population, then, higher density can result in dramatically lower total loadings than more diffuse suburban densities. The model showed that a simple doubling of standard suburban densities [to 8 dwelling units per acre (DUA) from about 3 to 5 DUA] in most cases could do more to reduce contaminant loadings associated with urban growth than many traditional stormwater best management practices (BMPs), and that higher densities such as those associated with transit-oriented development could outperform almost all traditional BMPs, in terms of reduced loadings per a constant population. Because higher density is associated with vibrant urban life, building a better city may be the best BMP to mitigate the water quality damage that will accompany the massive urban growth expected for the next several decades.